1. Field of the Invention
This invention relates to automatic one at a time sheet feed and withdrawal mechanisms for devices including business machines, data printers, and/or tele-printers.
2. Prior Art
Devices for moving data carrying sheets one at a time from the stack of sheets to a business machine and for receiving the sheets from the business machine and stacking them are known. A large number of such devices exist both for paper sheets and for cards. One particular problem which exists when dealing with stacks of sheets, such as a stack of paper, is the requirement of reliably separating the uppermost sheet from the stack and from the next sheet in the stack and conducting the sheet to a feed device for infeeding past a processing position. An additional problem area exists at the point where the data carrier is to be transferred from one feed device to the next feed device and particularly in the lateral guidance of the sheet along the guide track. Satisfactory alignment of the individual feed systems in a series of feed systems is of decisive importance to the extent that the output position of the sheet stack determines the further transportation path of the separated sheet.
Such data carrying sheets can, in fact, be reliably separated from one another by means of known devices. For example, in one type of known device, the upper most sheet of a stack of sheets can be lifted by a gripping device provided with a suction cup and can thereafter be fed to the next feed device. Although such devices are functional, they have a high initial cost. Another known device relies upon the use of friction drive for separation of the top sheet. These devices have an initial high cost for the guide tracks as well as for the mounting and positioning of the drive elements all of which are required to be relatively complex and precise in order to insure that the sheet will be positioned at the desired feed point with a relatively high degree of accuracy.
It would therefore be an advance in the art to provide an inexpensive, uncomplicated device for separating the uppermost sheet of a stack of sheets from the stack and delivering the sheet to a data processor or typewriter and for receiving the sheet from the data processor and stacking in a stack of processed sheets.